A special legislative committee is launching its own analysis of health care reform so the Legislature is in a position to take an independent look at reform proposals coming from Gov. Peter Shumlin next year.

Crucial questions remain about the single-payer health care system that the Shumlin administration is putting together, such as how much it will cost and how it will be paid for. Other questions involve mechanisms for controlling the rising cost of health care, which will be important in making the new system affordable.

The plan is for a new system to be in place by 2017, providing the state is able to gain waivers from the federal government allowing it to proceed. That means that the administration must introduce legislation in 2015, launching one of the most ambitious undertakings the Legislature has carried out in many years.

Already, Shumlin has irritated Republicans who note that he long ago missed the legal deadline by which he was required to reveal his funding plan for the new system. Shumlin has been on the cavalier side in ignoring the deadline, saying it would be premature of him to reveal a plan that is still not drawn up.

It was also politically advantageous for Shumlin not to reveal his plans because he did not have to defend them in the previous election and will not have to in the election later this year. But that advantage is seeping away. In the absence of information from the administration, critics have had time to promote alternative ways of thinking about the coming challenge.

We are hearing more from members of the Legislature about a Plan B or a Plan A, or any number of plans, that the Legislature could have recourse to if the numbers coming from Shumlin don’t add up this winter. One of the dangers for Shumlin is that the state has already taken significant steps to extend health care by adopting the new exchange, Vermont Health Connect, under the aegis of the federal Affordable Care Act. Critics can argue that the health care system, while not perfect, has made progress and so it is not worthwhile overturning the applecart by adopting a single-payer system.

Proponents of single-payer counter that Vermont Health Connect was meant only as a bridge to a new universal and inclusive system that does not rely on private health insurance. Under the new system, Vermonters would no longer have to buy insurance at all; they would get health care coverage the way that senior citizens do under Medicare — through a government system.

Critics say that this new system will require a massive tax hike, which is true, but those new taxes would be offset by the elimination of health care premiums, which take a sizable chunk out of people’s paychecks and out of the bottom lines of businesses. Further, the single-payer system would create significant cost-saving efficiencies by eliminating the paper chase of private insurance.

And yet the numbers showing that this will work as planned are still not forthcoming. Now the Legislature as a co-equal branch of government has launched its own study that it can use as it takes up the governor’s proposal in January. It is a necessary and important exercise for the Legislature to undertake.

Meanwhile, Shumlin is courting trouble if he is following the Clinton example. Recall that in the early ’90s President Bill Clinton, with the first lady in charge, developed a health care plan behind closed doors, dumping it on Congress as a fait accompli. Congress ended up defeating what was dismissed at the time as Hillarycare.

Shumlin’s plan is taking shape behind closed doors, and while there is no reason to believe anything problematic is happening, there has been little opportunity for buy-in by legislators or the public. Even the chairman of the Green Mountain Care Board, Al Gobeille, has voiced the view that cost containment remains the key to future health care reform, suggesting that if Shumlin’s proposal does not guarantee cost containment adequately, it could slow progress for the single-payer plan.

Shumlin is poised to advance a historic legislative proposal, and with strong Democratic majorities in the Legislature passage would seem all but guaranteed. But Democrats in the Legislature are aware that it is incumbent upon them to ensure that they and the governor don’t get carried away by their enthusiasm and that the plan they settle on will be successful.

Until now the Legislature’s record in standing up to Shumlin has been mixed. On health care reform it needs to make sure that the common ground it is able to find with the governor is solid.